Electric furnace.



T. P. BAILY.

ELECTRIC FURNACE.

APPLICATION FILED 0G1.13,1908,

Patented Sept. 14-, 1909.

anion THADDEUS r. DAILY, or ALLIANCE, OHIO.

ELEGTRIC FURNKEE.

Specification of Letters Patent.

Patented Sept. ilt, race.

Application filed October 13, 1903. Serial No. 457,458.

To all whom it may concem:

Be it known that I, THADDEUS F. BAILY, a citizen of the United States,residing at Alliance, in the county of Stark and State of Ohio,haveinvented certain new and useful Improvements in Electric Furnaces;and I do declare the following to be a full, clear, and exactdescription of the invention, reference' being had to the accompanyingdrawing, and to the numerals of reference marked thereon, which form apart of this specification.

This invention relatesto electric furnaces and has for its object theproduction of a furnace which will yield a great amount of heatdeveloped from a given strength of current and at the same time save therapid oxidation of the core. 5

in the accompanying drawing: Figure 1 is a longitudinal section. Fig. 2is a transverse section. Fig. 3 is a top view showing the top or coverof the furnace removed.

Similar numerals of reference indicate corresponding parts in all thefigures of the drawing. I

In the accompanying drawing, 1 represents a metallic base or foundationupon which the furnace structure is built. The base 1 is for the purposeof bringing the furnace into proper elevation for use and such use ashereinafter described, and hence the metal base 1, may be dispensed withif desired and the furnace built upon a nonmetallic or brick foundationif desired.

The furnace proper is constructed of nonmetallic heat resisting and lowelectrical conducting material 2 and fire brick 3, and the brick soarranged with reference to each other that an ovenor chamber will beformed just below the top or cover of the furnace proper and also airchambers, which chambers are for the purpose hereinafter described.

For the purpose of providing better or perfect insulation strips ofasbestos 4 should be embedded in the furnace wall proper preferably justbelow the tier of brick constituting the bottom of the oven; but ifdesired, additional strips of asbestos may be employed without departingfrom the nature of my invention.

At opposite ends of the furnace proper are located the electrodes 5,which electrodes are preferably located as shown in Figs. 1 and 3.Between the electrodes 5 and in proper contacttherewith is located aresistance body of charcoal, or coke or like material 6, which body ofcharcoal or coke is in granular form and located in direct contact withthe nonmetallic bottom of the oven or furnace chamber. The electrodes 5are located. in the path of the circuit as conventionally shown in Fig;3 and as shown the body of charcoal or coke is located in the path ofthe circuit and between the electrodes.

It should be noted that the electrodes 5 are of-considerable verticaldimension and of considerable width, thus presenting a relatively largesurface for contact with the resistance body 6. It will be noted by aninspection of Fig. 1 that the said body 6 diminishes in verticalthickness from the said electrodes toward the center of said body, thebody 6 in the middle of the furnace being of considerably lesscross-section than at its ends where contact is made with the saidelectrodes. By this construction it will readily be understood by thoseskilled in the art that the resistance in the body 6 will be greater inthe center than at. the ends of said body adjacent the electrodes. Inthis way rapid oxidation of the said body adjacent said electrodes andrapid oxidation of said electrodes is prevented while at. the same timeconcentrating the heat in the center of the furnace where it is desired.

F or the purpose of providing proper electric and also thermalinsulation the side Walls of the furnace are provided with the airspaces 7 and the wall below the heating chamber or oven is provided withthe air spaces 7, which spaces provide better insulation and especiallyso if the brick should be come more conductive from excessive heat or ifsaid brick from long use should become changed in such manner that thecurrent might be shunted from the resistance body to the brick wall ofthe furnace proper.

Que side of the furnace wall is provided with the opening 8, whichopening is for the purpose of inserting metallic bars to be heated, andfor the purpose of holding the metallic bars out of Contact with theelectrically charged body of coal or coke, the shoulder 9 is provided,which shoulder or ledge is for the purpose of holding the inner ends orportions of the bars in proper eleva tion so that the current will notbe shunted to the metallic bars.

The furnace illustrated in the drawings is one specifically designed forthe heating of metallic ,bars, but it will be understood that thes'amegeneral plan and arrangement can be carried out for heating ingots.

It will'be noted from the above descrip-- tion that by the constructiondisclosed an electric furnace is produced wherein the resistance'bodymay be readily and cheaply renewed, in which the said resistance bodywill not readily burn away from the electrodes and in which the saidelectrodes will be kept at a comparatively low temperature. The factshould also be noted, that there is nothing interposed between theincandescent resistance body acted on by the current and the material tohe heated and that the said material to be heated is located above thesaid resistance body, thereby being in the most advantageous positionfor the accomplishment of good results.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. An electric furnace comprising nonmetallic walls forming a heatinchamber, electrodes held in spaced relat1on within said chamber, aresistance body located on the bottom of said heating chamber and incontact with said electrodes, the area of contact between each of saidelectrodes and said body and the area of the cross-section of said bodyadjacent said electrodes being greater than the area of thecross-section of said body substantially midway between said electrodes,one of the walls of the furnace provided with an opening and theopposite wall provided with a ledge, the upper surface of said ledge andthe bottom of said 0 ening being located above the top surface of saidresistance body, said ledge and the bottom of said opening adapted tosupport material to be heated.

2. An electric furnace comprising a base, furnace walls arran ed uponsaid base and composed of heat resisting and low electrical conductingbrick arranged in tiers with strips of asbestos between adjacent tiers,said bricks arranged to form an oven, spaced electrodes located in saidoven, a resistance body located upon the bottom of the interior of saidoven and extending from one to the other of said spaced electrodes andin contact therewith, the area of contact between each of saidelectrodes and said body and the area of the cross-section of said bodyadjacent said electrodes being greater than the area of thecross-section of said body substantially midway between said electrodes,one of the walls of the furnace provided with an opening and theopposite wall provided with a ledge, the upper surface. of said ledgeandthe bottom of said opening being located above the top surface of saidresistance body.

3. An electric furnace comprising a base,

furnace walls arranged upon said base and composed of heat resisting andlow electrical conducting bricks arranged in tiers with strips ofasbestos between adjacent tiers, said bricks arranged to form an oven,spaced electrodes located in said oven, and a resistan'ce body locatedupon the bottom of the interior of said oven and extending from one tothe other of said spaced electrodes and in contact therewith.

4. An electric furnace comprising a base, furnace walls, said furnacewalls composed of heat resisting and low electrical conducting bricksarranged to constitute an oven, electrodes spaced from each other andlocated in said oven, a resistance body located upon the bottom of theinterior of said oven and extending from one end to the other betweenthe electrodes and in contact therewith, the area of contact betweeneach of said electrodes and said body and the area of cross-section ofsaid body adjacent said electrodes being greater than the area of thecross section of said body substantially midway between said electrodes,one of the walls of the furnace provided with an opening.

5. An electrical furnace comprising a base, furnace walls, said furnacewalls composed ofv heat resisting and low electrical conducting bricksarranged to constitute an oven, electrodes spaced from each other andlocated in said oven, a resistance body located upon the bottom of theinterior of said oven and extending from one end to the other betweenthe electrodes and in contact therewith, said resistance body composedof material in granular form, the area of contact between each of saidelectrodes and said body and the area of cross-section of said bodyadjacent said electrodes being greater than the area of the crosssection of said body substantially midway between said electrodes, oneof the walls of the furnace provided with an opening.

In testimony that I claim the above, I have hereunto subscribed my namein the presence of two witnesses.

, THADDEUS F. BAILY.

Witnesses:

W. W. MATCHETT,

B. Fnncnson.

